1. Field of the Invention
The present invention relates to a refillable ink ribbon cartridge for use in an electronic typewriter or a printer and more particularly, to an ink ribbon cartridge for use in an electronic typewriter which includes a changeable feed spool easily replaced through and a winding spool about which is wound a used ribbon which is easily taken out of the cartridge through a casing cover opening on a casing cover of the cartridge, whereby the used cartridge can be reused without creating waste materials.
2. Description of the Prior Art
Various types of disposal ink ribbon cartridges are well known in the art. For example, in such disposal ink ribbon cartridges, the feed spool and the winding spool are operatively maintained the resilience of an ink ribbon by a feed spool spring as described in U.S. Pat. No. 4,406,554 to Nally et al and U.S. Pat. No. 4,655,623 to Gasser. However, such ink ribbon cartridges are incapable of allowing replacement of the feed spool and must be thrown away with the used ribbon after one use so as to create large amounts of waste materials.
In order to avoid such problems, the present inventor is prosecuting U.S. patent application Ser. No. 07/426,670, filed Oct. 26, 1989, which disclosed a refillable ink ribbon cartridge for use in an electronic typewriter which includes a housing, a feed spool member having symmetric C-shaped springs for slidably receiving and removing a changeable feed spool, a winding spool member having a lever and a lever opener for slidably inserting and removing a winding spool, and a jagged wheel whereby the used ink ribbon cartridge can be reused and maintains a constant tension on the ink ribbon between the feed and winding spools.